This guide is for anyone who has a "Stock Gingerbread" Rom on a G2, Desire Z, or myTouch 4G phone, allowing them to downgrade to the original Stock Froyo Rom.
Okay, this is my first time writing a guide, I came across this method earlier today and haven't seen a "Guide" post on XDA. So I decided to make this post, writing each step by step as best as I can. This is for G2 users who have upgraded to the 2.13.531.8 T-Mobile release and have S-ON. Well, now there is a way to gain temp root access and revert back! This is the method I used, myself, to revert back to the Stock Froyo Rom.
This guide is written with the assumption that the user has previously used "adb". If you are unfamiliar with "adb" or do not even know what "adb" is, download the Android SDK (found at
Android SDK | Android Developers). There are a couple guides to help you get started setting up the Android SDK and understanding ADB. If you have not installed the Android SDK or you are unfamiliar with ADB, please take some time and read a couple guides to get a basic understanding of it.
Gaining Temp Root
- Download the attached files, unzip them, and place the files in your platform-tools folder. To elaborate, place the fre3vo file inside of the fre3vo.zip file and the misc_version file inside the misc_version_01.zip file in your platform-tools directory.).
- Make sure you have your sdcard inserted in your phone, and you are NOT in USB Storage Mode, and your sdcard is NOT FULL.
- Run the following command to verify the exploit has access to what it needs. (Only the first line is the command. The second line should be the result returned if all goes well.)
Code:
[B]$ adb shell cat /dev/msm_rotator[/B]
[I]/dev/msm_rotator: invalid length[/I]
- If you received the same message, you're good to continue on. If not... I'd recommend going back to #g2root and asking them. (I am just passing along the information after all).
- Run the following commands from your platform-tools directory.
Code:
[B]$ adb push fre3vo /data/local/tmp
$ adb shell
$ chmod 777 /data/local/tmp/fre3vo
$ /data/local/tmp/fre3vo -debug -start FAA90000 -end FFFFFFFF[/B]
- After you enter that command, with luck you should see something similar to the last few lines in the following displayed. (It may take a minute or two. From what I can tell, this appears to be the quickest method as the exploit seems to be found in the latter regions.)
Code:
[I]Buffer offset: 00000000
Buffer size: 8192
Scanning region fb7b0000...
Scanning region fb8a0000...
Scanning region fb990000...
Scanning region fba90000...
Potential exploit area found at address fbb4d600:a00.
Exploiting device...[/I]
- If the exploit works, you will be kicked out of ADB shell, proceed to Step #7.
- If the above does not work, and fails, you can try the following, and hopefully one will work, try the following (you must reboot your phone before you try another set):
Code:
[B]$ /data/local/tmp/fre3vo -debug -start 10000000 -end 1FFFFFFF
$ /data/local/tmp/fre3vo -debug -start 20000000 -end 2FFFFFFF
$ /data/local/tmp/fre3vo -debug -start 30000000 -end 3FFFFFFF
$ /data/local/tmp/fre3vo -debug -start F0000000 -end FFFFFFFF
$ /data/local/tmp/fre3vo -debug -start E0000000 -end EFFFFFFF[/B]
- If you did get kicked out of adb shell, open it again. You should now see the lovely # instead of $, thus granting you temp root. Go ahead and exit out of shell to proceed to the next stage.
Code:
[B]$ adb shell
# exit[/B]
Changing Version Number to Allow Downgrade
- If you followed the first portion of this, you should of unzipped misc_version_01.zip in the platform-tools directory.
If you haven't done that yet, do that now and then run the following commands from your platform-tools directory.
-
Code:
[B]$ adb push misc_version /data/local/tmp/misc_version[/B]
[B]$ adb shell chmod 777 /data/local/tmp/misc_version[/B]
[B]$ adb shell[/B]
[B]# /data/local/tmp/misc_version -s 1.00.000.0[/B]
[I]--set_version set. VERSION will be changed to: 1.00.000.0
Patching and backing up partition 17...[/I]
*Note: If you get the following error, please make sure your sdcard is inserted in your phone and is NOT mounted to your computer (ie: make sure you are NOT in USB Storage Mode).
Code:
Error opening backup file.
-
- Double check and make sure everything looks good so far by running the following command (still in adb shell).
Code:
[B]# dd if=/dev/block/mmcblk0p17 bs=1 skip=160 count=10[/B]
[I]1.00.000.010+0 records in
10+0 records out
10 bytes transferred in 0.001 secs (10000 bytes/sec)[/I]
- BE SURE TO BACKUP ANY DATA!!!***
Downgrading
- Download the Stock Rom for the G2 (PC10IMG_Vision_TMOUS_1.19.531.1_Radio_12.21.60.09b_26.02.01.15_M2_release_149459_signed.zip) and save it to platform-tools directory as well. The Stock Rom can be found here: Multiupload.com - upload your files to multiple file hosting sites!
- Push it to your sdcard and reboot into bootloader with the following commands:
Code:
[B]$ adb push PC10IMG_Vision_TMOUS_1.19.531.1_Radio_12.21.60.09b_26.02.01.15_M2_release_149459_signed.zip /sdcard/PC10IMG.zip
$ adb reboot bootloader[/B]
- Download the Stock Rom for the DZ (1.34.405.5_PC10IMG.zip) and save it to platform-tools directory as well. The Stock Rom can be found here: Multiupload.com - upload your files to multiple file hosting sites!
- Push it to your sdcard and reboot into bootloader with the following commands:
Code:
[B]$ adb push 1.34.405.5_PC10IMG.zip /sdcard/PC10IMG.zip
$ adb reboot bootloader[/B]
- Download the Stock Rom for the myTouch 4G (PD15IMG.zip) and save it to platform-tools directory as well. The Stock Rom can be found here: MEGAUPLOAD - The leading online storage and file delivery service
- Push it to your sdcard and reboot into bootloader with the following commands:
Code:
[B]$ adb push PD15IMG.zip /sdcard/PD15IMG.zip
$ adb reboot bootloader[/B]
- Your phone should now reboot into the bootloader. If The first option should say "BOOTLOADER" highlighted in blue, select that by pressing the power button. It will now scan the sdcard for PC10IMG.zip (or PD15IMG.zip if you are using myTouch 4G). Once it does, it will ask you to update.
- Press the `Volume Up` button to begin the update (or in this case, downgrade). When this has finished, you can reboot and you'll be back with the Stock Rom and you can now root from there, which there are plenty of other guides to go by on how to do that.
Sources:
If anyone needs further help and would prefer messaging me, feel free.
Troubleshooting
I wanted to give credit to specific individuals whom have helped write this guide, provided important feedback to further improve this guide, and/or in any other way further improved this guide. I think these invidiuals should be recognized, as if it were not for them, this would wouldn't be as elaborate, dynamic, and informative as it is. So a special thanks to,
Cimer,
petarpLab,
iDylan1357,
asharma5290
Change Log
- 2011/08/26
- Changed modified version number for each device to 1.00.000 as it is more universal and works for each one.
- Made it more clear to extract the attached files and place them in the platform-tools directory for use.
- 2011/08/06
- Added a couple links to ADB guide.
- 2011/08/05
- Added myTouch 4G
- Added link to an "adb" guide.
- Changed title from "[GUIDE] Downgrade G2 2.13.531.8 (2.3.3 T-Mobile Rom w/ S-ON) & DZ 2.3.3 w/ S-ON" to "[GUIDE] Downgrade G2 (2.3.3) & DZ (2.3.3) & mT4g (2.3.4) w/ S-ON to Stock Froyo"
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